MFCreateTranscodeProfile function (mfidl.h)

Article
10/13/2021

Creates an empty transcode profile object.

The transcode profile stores configuration settings for the output file. These configuration settings are specified by the caller, and include audio and video stream properties, encoder settings, and container settings. To set these properties, the caller must call the appropriate IMFTranscodeProfile methods.

The configured transcode profile is passed to the MFCreateTranscodeTopology function. The underlying topology builder uses these settings to build the transcode topology.

Syntax

HRESULT MFCreateTranscodeProfile(
  [out] IMFTranscodeProfile **ppTranscodeProfile
);

Parameters

[out] ppTranscodeProfile

Receives a pointer to the IMFTranscodeProfile interface of the transcode profile object. Caller must release the interface.

Return value

If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

The MFCreateTranscodeProfile function creates an empty transcode profile. You must configure the transcode profile setting attributes that define the media types and the container properties. Use the following methods to configure the profile:

For example code that uses this function, see the following topics:

Examples

The following example creates a transcode profile for Windows Media Audio (WMA).

template <class Q>
HRESULT GetCollectionObject(IMFCollection *pCollection, DWORD index, Q **ppObj)
{
    IUnknown *pUnk;
    HRESULT hr = pCollection->GetElement(index, &pUnk);
    if (SUCCEEDED(hr))
    {
        hr = pUnk->QueryInterface(IID_PPV_ARGS(ppObj));
        pUnk->Release();
    }
    return hr;
}

HRESULT CreateTranscodeProfile(IMFTranscodeProfile **ppProfile)
{
    IMFTranscodeProfile *pProfile = NULL;     // Transcode profile.
    IMFCollection   *pAvailableTypes = NULL;  // List of audio media types.
    IMFMediaType    *pAudioType = NULL;       // Audio media type.
    IMFAttributes   *pAudioAttrs = NULL;      // Copy of the audio media type.
    IMFAttributes   *pContainer = NULL;       // Container attributes.

    DWORD dwMTCount = 0;
    
    // Create an empty transcode profile.
    HRESULT hr = MFCreateTranscodeProfile(&pProfile);
    if (FAILED(hr))
    {
        goto done;
    }

    // Get output media types for the Windows Media audio encoder.

    // Enumerate all codecs except for codecs with field-of-use restrictions.
    // Sort the results.

    DWORD dwFlags = 
        (MFT_ENUM_FLAG_ALL & (~MFT_ENUM_FLAG_FIELDOFUSE)) | 
        MFT_ENUM_FLAG_SORTANDFILTER;

    hr = MFTranscodeGetAudioOutputAvailableTypes(MFAudioFormat_WMAudioV9, 
        dwFlags, NULL, &pAvailableTypes);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pAvailableTypes->GetElementCount(&dwMTCount);
    if (FAILED(hr))
    {
        goto done;
    }
    if (dwMTCount == 0)
    {
        hr = E_FAIL;
        goto done;
    }

    // Get the first audio type in the collection and make a copy.
    hr = GetCollectionObject(pAvailableTypes, 0, &pAudioType);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = MFCreateAttributes(&pAudioAttrs, 0);       
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pAudioType->CopyAllItems(pAudioAttrs);
    if (FAILED(hr))
    {
        goto done;
    }

    // Set the audio attributes on the profile.
    hr = pProfile->SetAudioAttributes(pAudioAttrs);
    if (FAILED(hr))
    {
        goto done;
    }

    // Set the container attributes.
    hr = MFCreateAttributes(&pContainer, 1);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pContainer->SetGUID(MF_TRANSCODE_CONTAINERTYPE, MFTranscodeContainerType_ASF);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pProfile->SetContainerAttributes(pContainer);
    if (FAILED(hr))
    {
        goto done;
    }

    *ppProfile = pProfile;
    (*ppProfile)->AddRef();

done:
    SafeRelease(&pProfile);
    SafeRelease(&pAvailableTypes);
    SafeRelease(&pAudioType);
    SafeRelease(&pAudioAttrs);
    SafeRelease(&pContainer);
    return hr;
}

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	mfidl.h
Library	Mf.lib
DLL	Mf.dll

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